Even when times are booming and there is a demand for more output, employers may work their existing employees longer hours rather than hire new workers whom they will have a hard time letting go after the boom passes.
Nothing is easier for politicians than to think up benefits that they can confer on workers by imposing the costs on somebody else. It's something-for-nothing time, and it pays off for politicians at election time.
Meanwhile, businesses can't just pick up and leave the city or the state, much less the country, overnight. But, like the South African company that expanded its output and employment in Poland, businesses can do their expansion where costs imposed on them by politicians are not so high.
Some businesses are not expanding but are just trying to survive. Costs blithely loaded onto them by politicians can prevent some of these kinds of businesses from surviving -- and their employees lose their jobs.
Over time, businesses can shift more and more of their operations out of places where extra costs are imposed politically and some just move their whole business elsewhere. That means taking their jobs, and the taxes they pay, elsewhere.
For politicians, however, killing the goose that lays the golden eggs is a viable strategy, provided that the goose doesn't die before the next election. Provided also that people have short memories, don't connect the dots, and don't keep in mind that there is no such thing as something for nothing.